Accessing a combobox item after TextChanged event results in an object disposed exception [C# .NET 4.6]

Question

The Problem

I'm currently working on a form in which the datagridview cell takes it's input from syncfusion's multicolumncombobox tool and everything works as intended until I erase the multicolumncombobox's textbox and then select something else

This is the sequence I follow

1. I erase the multicolumncombobox textbox's text
2. I select a new value from the combobox(SelectedValueChanged event)
3. An exception is thrown (Unhandled Exception despite being in a try/catch block)

The Exception

See the end of this message for details on invoking



just-in-time (JIT) debugging instead of this dialog box.







************** Exception Text **************



System.ObjectDisposedException: Cannot access a disposed object.



Object name: 'ComboBoxPopupContainer'.



   at System.Windows.Forms.Control.CreateHandle()



   at System.Windows.Forms.Control.get_Handle()



   at System.Windows.Forms.Control.PointToClientInternal(Point p)



   at System.Windows.Forms.Control.PointToClient(Point p)



   at Syncfusion.Windows.Forms.Tools.ComboDropDown.ComboDropDown_Deactivate(Object sender, EventArgs e)



   at System.Windows.Forms.Form.OnDeactivate(EventArgs e)



   at System.Windows.Forms.Form.set_Active(Boolean value)



   at System.Windows.Forms.Form.DeactivateMdiChild()



   at System.Windows.Forms.Form.WmMdiActivate(Message& m)



   at System.Windows.Forms.Form.WndProc(Message& m)



   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)



   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)



   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)











************** Loaded Assemblies **************



mscorlib



    Assembly Version: 4.0.0.0



    Win32 Version: 4.8.4470.0 built by: NET48REL1LAST_C



    CodeBase: file:///C:/Windows/Microsoft.NET/Framework/v4.0.30319/mscorlib.dll



----------------------------------------



MDIForm



    Assembly Version: 1.0.0.0



    Win32 Version: 1.0.0.0



    CodeBase: file:///D:/Project/bsp_winforms/bsp_winforms/bin/Debug/MDIForm.exe



----------------------------------------



Syncfusion.Licensing



    Assembly Version: 19.4460.0.53



    Win32 Version: 19.4460.0.53



    CodeBase: file:///D:/Project/bsp_winforms/bsp_winforms/bin/Debug/Syncfusion.Licensing.DLL



----------------------------------------



System.Windows.Forms



    Assembly Version: 4.0.0.0



    Win32 Version: 4.8.4400.0 built by: NET48REL1LAST_C



    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Windows.Forms/v4.0_4.0.0.0__b77a5c561934e089/System.Windows.Forms.dll



----------------------------------------



System



    Assembly Version: 4.0.0.0



    Win32 Version: 4.8.4360.0 built by: NET48REL1LAST_C



    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System/v4.0_4.0.0.0__b77a5c561934e089/System.dll



----------------------------------------



System.Drawing



    Assembly Version: 4.0.0.0



    Win32 Version: 4.8.4390.0 built by: NET48REL1LAST_C



    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Drawing/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll



----------------------------------------



Syncfusion.Shared.Base



    Assembly Version: 19.4460.0.53



    Win32 Version: 19.4460.0.53



    CodeBase: file:///D:/Project/bsp_winforms/bsp_winforms/bin/Debug/Syncfusion.Shared.Base.DLL



----------------------------------------



System.Xml



    Assembly Version: 4.0.0.0



    Win32 Version: 4.8.4084.0 built by: NET48REL1



    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Xml/v4.0_4.0.0.0__b77a5c561934e089/System.Xml.dll



----------------------------------------



System.Configuration



    Assembly Version: 4.0.0.0



    Win32 Version: 4.8.4190.0 built by: NET48REL1LAST_B



    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Configuration/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll



----------------------------------------



System.Core



    Assembly Version: 4.0.0.0



    Win32 Version: 4.8.4470.0 built by: NET48REL1LAST_C



    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Core/v4.0_4.0.0.0__b77a5c561934e089/System.Core.dll



----------------------------------------



Syncfusion.Tools.Windows



    Assembly Version: 19.4460.0.53



    Win32 Version: 19.4460.0.53



    CodeBase: file:///D:/Project/bsp_winforms/bsp_winforms/bin/Debug/Syncfusion.Tools.Windows.DLL



----------------------------------------



Syncfusion.Grid.Windows



    Assembly Version: 19.4460.0.53



    Win32 Version: 19.4460.0.53



    CodeBase: file:///D:/Project/bsp_winforms/bsp_winforms/bin/Debug/Syncfusion.Grid.Windows.DLL



----------------------------------------



Accessibility



    Assembly Version: 4.0.0.0



    Win32 Version: 4.8.4084.0 built by: NET48REL1



    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/Accessibility/v4.0_4.0.0.0__b03f5f7f11d50a3a/Accessibility.dll



----------------------------------------



System.Data



    Assembly Version: 4.0.0.0



    Win32 Version: 4.8.4455.0 built by: NET48REL1LAST_C



    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_32/System.Data/v4.0_4.0.0.0__b77a5c561934e089/System.Data.dll



----------------------------------------



System.Numerics



    Assembly Version: 4.0.0.0



    Win32 Version: 4.8.4084.0 built by: NET48REL1



    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Numerics/v4.0_4.0.0.0__b77a5c561934e089/System.Numerics.dll



----------------------------------------



UIAutomationProvider



    Assembly Version: 4.0.0.0



    Win32 Version: 4.8.4470.0 built by: NET48REL1LAST_C



    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/UIAutomationProvider/v4.0_4.0.0.0__31bf3856ad364e35/UIAutomationProvider.dll



----------------------------------------



WindowsBase



    Assembly Version: 4.0.0.0



    Win32 Version: 4.8.4470.0 built by: NET48REL1LAST_C



    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/WindowsBase/v4.0_4.0.0.0__31bf3856ad364e35/WindowsBase.dll



----------------------------------------



UIAutomationTypes



    Assembly Version: 4.0.0.0



    Win32 Version: 4.8.4470.0 built by: NET48REL1LAST_C



    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/UIAutomationTypes/v4.0_4.0.0.0__31bf3856ad364e35/UIAutomationTypes.dll



----------------------------------------



System.Runtime.Serialization.Formatters.Soap



    Assembly Version: 4.0.0.0



    Win32 Version: 4.8.4084.0 built by: NET48REL1



    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Runtime.Serialization.Formatters.Soap/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Runtime.Serialization.Formatters.Soap.dll



----------------------------------------







************** JIT Debugging **************



To enable just-in-time (JIT) debugging, the .config file for this



application or computer (machine.config) must have the



jitDebugging value set in the system.windows.forms section.



The application must also be compiled with debugging



enabled.







For example:







<configuration>



    <system.windows.forms jitDebugging="true" />



</configuration>



When JIT debugging is enabled, any unhandled exception   
will be sent to the JIT debugger registered on the computer    
rather than be handled by this dialog box.

And if keep clicking "continue" this stacktrace is shown before the application closes

Code

TextChanged event

private void aliasMulticolcombobox_TextChanged(object sender, EventArgs e)
{
    try
    {
        aliasMulticolcombobox.SelectedValueChanged += new EventHandler(aliasMulticolcombobox_SelectedValueChanged);
    }

    catch (Exception exception)
    {
        MessageBox.Show(exception.Message, "Exception", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
    }
}

SelectedValueChanged Event

private void aliasMulticolcombobox_SelectedValueChanged(object sender, EventArgs e)
{
    try
    {
        ComboBoxBaseDataBound c = aliasMulticolcombobox as ComboBoxBaseDataBound;


        if (c.SelectedIndex != -1)
        {
            DataRowView dv = c.Items[c.SelectedIndex] as DataRowView;
            c.Text = dv.Row[0].ToString();
            dataGridView1.Rows[currRow].Cells[1].Value = c.Text;
        }
    }






    catch (Exception exception)
    {


        MessageBox.Show(exception.Message, "Exception", MessageBoxButtons.OK, MessageBoxIcon.Error);


    }
}

What I have tried so far

1. Check if the combobox popup container is accessible by using the aliasMulticolcombobox.PopupContainer.IsAccessible() function
2. Check if the combobox popup container is disposed by using the aliasMulticolcombobox.PopupContainer.IsDisposed() function so I can return from the function
3. Tried the.BeforeCloseUp Event to cancel the dispose call
4. Tried switching event handlers

Despite all these efforts the same problem persists

Answer 1

I just got in touch with the Syncfusion developers and they responded by saying it's a bug

We have validated and confirmed the reported scenario is a defect and logged a report for the reported scenario “TargetParameterCountException was thrown when selecting the value in MultiColumnComboBox after clearing the text”. We will provide the patch for the reported issue on 25th March 2022.